Birthweight, HIV exposure and infant feeding as predictors of malnutrition in Botswanan infants

BACKGROUND

A better understanding of the nutritional status of infants who are HIV-Exposed-Uninfected (HEU) and HIV-Unexposed-Uninfected (HUU) during their first 1000 days is key to improving population health, particularly in sub-Saharan Africa.

METHODS

A cross-sectional study compared the nutritional status, feeding practices and determinants of nutritional status of HEU and HUU infants residing in representative selected districts in Botswana during their first 1000 days of life. Four hundred and thirteen infants (37.3% HIV-exposed), aged 6-24 months, attending routine child health clinics, were recruited. Anthropometric, 24-h dietary intake and socio-demographic data was collected. Anthropometric Z-scores were calculated using 2006 World Health Organization growth standards. Modelling of the determinants of malnutrition was undertaken using logistic regression.

RESULTS

Overall, the prevalences of stunting, wasting and being underweight were 10.4%, 11.9% and 10.2%, respectively. HEU infants were more likely to be underweight (15.6% versus 6.9%), (P < 0.01) and stunted (15.6% versus 7.3%), (P < 0.05) but not wasted (P = 0.14) than HUU infants. HEU infants tended to be formula fed (82.5%), whereas HUU infants tended to breastfeed (94%) for the first 6 months (P < 0.001). Significant predictors of nutritional status were HIV exposure, birthweight, birth length, APGAR (appearance, pulse, grimace, activity and respiration) score and mother/caregiver's education with little influence of socio-economic status.

CONCLUSIONS

HEU infants aged 6-24 months had worse nutritional status compared to HUU infants. Low birthweight was the main predictor of undernutrition in this population. Optimisation of infant nutritional status should focus on improving birthweight. In addition, specific interventions should target HEU infants aiming to eliminate growth disparity between HEU and HUU infants.

Effects of exercise and diet on weight loss maintenance in overweight and obese adults: a systematic review

Overweight and obesity are widespread nutritional disorders. Their treatment aims at effective weight loss (WL) and weight loss maintenance (WLM). Previous systematic reviews show weight regain, after recommended exercise and diet combined. However, certain experimental and methodological inconsistencies in the original studies and in these reviews left space for a substantial revisit of this problem. This study aimed at systematically re-reviewing the effectiveness of exercise combined with diet on WLM in overweight and obese adults. Literature was searched through Embase and Sport Discus (up to 2008), and PubMed (Medline) and ISI Web of science (up to 2012). 14 randomized clinical trials (RCT) were retained, their quality was assessed by the Jadad scale, and detailed methodological and statistical characteristics were evaluated. Overall estimations showed a WL of 11.1 kg (about 13%) after an average of about 4 months from baseline, a WLM of 5.8 kg (about 52%) and a weight regain of 5.1 kg after an average period of about 21 months. WL was successful but almost half of it (about 48%) was regained, which agrees with previous findings. The Jadad score showed very good to excellent quality for all 14 studies. However, further assessment revealed serious weakness such as high average dropout (>20%), not estimating experimental power or not using a control group in more than half of the studies, possible lack of adherence and variability in demographic traits. Future studies may focus on improving these limitations for more accurate results in this crucial research field.

Effect of gestational nutrition on vascular integrity in the murine placenta

Maternal undernutrition is thought to result in smaller offspring and programme disease in later life. It is not known whether gestational nutrition affects development and functioning of placental vessels. The aim of this study was to ascertain if disturbed angiogenesis and junctional integrity were features of the labyrinthine vessels of placenta taken from transgenic Tie2-GFP mice fed either 18% (control) or 9% (low protein; MLP) casein diet. MLP animals showed a significant decrease in fetal weight at E14.5 and in placental and fetal weight at E18.5, however, maternal weight and litter size remained unaffected. Stereological analyses revealed that the fraction of components of the placenta remained similar in both study groups. There was a significant reduction in labyrinthine blood vessel length but not in luminal diameter in the E18.5 MLP group. In both MLP groups, perturbation of vascular endothelial Cadherin and beta-catenin, regulators of junctional integrity, permeability and quiescence, was observed with higher percentage of vessels showing weak or no junctional immunoreactivity. The reduction in length of the labyrinthine vessels and the downregulation of the adhesion molecules suggest that gestational undernutrition causes vascular dysfunction in the murine placenta. This may play a role in the early life programming of disease risk.

Intrauterine exposure to a maternal low protein diet reduces adult bone mass and alters growth plate morphology in rats

Epidemiological studies suggest that poor growth during fetal life and infancy is associated with decreased bone mass in adulthood. However, theses observations have not, to date, been corroborated in animal models. To address this issue we evaluated the influence of maternal protein restriction on bone mass and growth plate morphology among the adult offspring, using a rat model. Maternal protein restriction resulted in a reduction in bone area and BMC, but not BMD, among the offspring in late adulthood. The widened epiphyseal growth plate in the protein-restricted offspring is compatible with the programming of cartilage and bone growth by maternal nutrition in early life.

Prenatal exposure to a maternal low protein diet shortens life span in rats

BACKGROUND

Postweaning diet restriction is associated with prolongation of life span, reduced age-related disease and slower ageing. The effects of diet restriction imposed prior to weaning have not been so well characterised, but studies suggest an opposite effect with increased age-related diseases occurring in offspring exposed to undernutrition in prenatal life. It remains unclear whether life span is similarly adversely affected by early diet restriction.

OBJECTIVE

The present study in rats aimed to evaluate the impact of a maternal low protein diet upon the life span of the resulting offspring.

METHODS

Rat dams were fed either a 180-gram casein/kg control diet or a 90-gram casein/kg low protein diet from conception until the end of pregnancy. The offspring were then maintained with minimal handling until death from natural causes or distress-necessitated euthanasia.

RESULTS

The average life span of female rats exposed to low protein diets in utero was reduced by 11% (p = 0.044, Kaplan-Meier analysis). There was a similar but non- significant trend in the male offspring (control 76 +/- 3 weeks, low protein 73 +/- 3 weeks). In addition the rats exposed to a prenatal low protein diet had significantly higher systolic blood pressure at 4 weeks of age and tended to be smaller than control animals in postnatal life.

CONCLUSION

The results suggest that intrauterine diet restriction reduces life span in rats and contrasts with the well-recognised increase in life span produced by postweaning diet restriction. The timing of the nutritional intervention appears to be critical and recognition of this is relevant to understanding the mechanisms underlying the effects of diet restriction on ageing and life span.

Intrauterine programming of hypertension: nutrient-hormone interactions

Geographic, retrospective, and prospective epidemiologic studies have revealed evidence that the environment in utero is a major determinant of later degenerative disease. Observations from Britain, Sweden, Jamaica, Australia, India, and China support the hypothesis that disproportionate retardation of fetal growth results in increased blood pressure and increased risk of cardiovascular mortality. On the basis of what has been a limited pool of observations linking maternal undernutrition and fetal growth retardation, it has been proposed that hypertension and coronary heart disease are "programmed" by nutrition status.